Elastic infusible products from epoxy compounds and cross-linking agents



United States Patent 0 8 bad ELASTIC BNFUSIBLE PRQBU CTS FRQM EPOXY CGMPOUNDS AND CR SS-LENIQNG AGENTS Willy Fisch, Einniugen, Switzerland, assignor to Ciba Limited, Basel, Switzerland, a Swiss firm No Drawing. Application August 4, 1950, Serial No. 177,774

Claims priority, application Switzerland August 12, 1949 15 Claims. (Cl. Zdil-dSJ-i) it is known that compounds which contain at least two epoxide groups per mol can be converted into infusible artificial resins by means of cross-linking agents, such for example as polycarboxylic anhydrides, hardening taking place practically without the formation of volatile byproducts and with only very slight shrinkage. Owing to their mechanical properties and chemical resistance such products are of considerable interest as cast products, lacquers or adhesives, especially for metals. As cross-linking agents there have been used only compounds in which the distance between the groups capable of reacting with epoxide groups is small.

However, in addition to their good properties for certain purposes the products so obtained have the disadvantage that they are not sufiiciently extensible and elastic.

The present invention is based on the observation that valuable artificial masses can be made by mixing a compound containing more than one epoxide group per mol with a cross-linking agent, and if desired, a catalyst, provided that certain requirements are observed. These requirements are that the linking agent used must be a compound containing at least two groups capable of reacting with epoxide groups, and these reactive groups must be separated from one another by a chain of at least l0, preferably at least 14-, and advantageously at least 24, members. The artificial masses so obtained can be converted by heat, if desired, with the aid of catalysts, into useful artificial products.

Thus, depending on the nature of the artificial mass and on the manner in which it is treated, there can be obtained as an intermediate stage fusible and inelastic artificial products, which can be converted by further treatment at a later stage into fusible and elastic products, and especially into infusible final products of surprising elasticity. Obviously, such linal products can be obtained in one operation from tire artificial masses. The degree of elasticity can be varied within wide limits. it depends on the quantity of the or ss-linking agent used, on the number and nature of the members between the active groups in the cross-linking agent and also on the distance apart of the epoxide groups in the cornpcund containing such groups. The elasticity can also be strongly influenced by using, in addition to a crosslinking agent in which a chain of at least 10 members separates the reactive groups, one in which those groups are separated by a chain having less than 10 members. in general, in this manner the modulus of elasticity is increased and the length to which this material can be drawn out before breaking reduced.

As groups, hereinafter also referred to as active groups, capable of reacting with epoxide groups, there may be used principally groups containing active hydrogen, for example, radicals of acid or alkaline action, such as carboxyl, sulpho, phosphoric acid or amino or amido or imino or imido groups. The acid groups may be present in the form of anliydrides or in another form which is easily convertible into the free acid. However, there may also be used aliphatic or aromatic hydroxyl-groups generally requiring more extreme reaction conditions such as a higher temperature or the use of catalysts.

The active groups of the cross-linking agent may be bound together by a very wide variety of different kinds of members, such as l l -(I2-, -0-, -s-, N- or aliphatic, aromatic or heterocyclic rings etc. Rigid rings such, for example, as benzene rings, are reckoned as one member.

As cross nlting agents which are compounds containing at least two groups capable of reacting with epoxide groups, these reactive groups being separated by a chain of at least l0 members, there are to be understood herein the following products which are known in the literature or can be made by the ordinary methods:

I. Unitary compounds.

ll. Mixtures, for examples, polyesters or polyarnides, such as are obtained, for example, by reacting polyhydric alcohols, advantageously (ll-alcohols, or polyarnines, advantageously diarnines, with polycarboxylic acids, advantageously dicarboxylic acids, or their anhydrides, and

Ill. Mixtures of cross-linking agents, of which the reactive groups are separated from one another by a chain of less than 10 members, for example, triethylene tetramine or phthalic anhydride, with compounds or mixtures as mentioned under 1 or H above.

Especially suitable as cross-linking e ents are long chain polyesters containing active groups. These can be obtained in a very simple manner by heating dicarboxylic acids with dialcohols, the length of the chain and also the nature of the end groups depending on the molecular ratio of the starting materials.

Into polyesters so obtained other active groups may be subsequently introduced, or active groups which are already present may be converted into other active groups. Thus, for example, in the case of a long chain polyester having end carboxyl groups, the latter maybe converted into the corresponding amide groups.

Cross-linking agents may also be formed in the presence of compounds containing epoxide groups, whereby the new artificial products can be obtained in one operation.

As compounds containing more than one epoxide group per mol there are to be understood not only chemical unitary compounds but also mixtures of compounds containing epoxide groups such, for example, as are obtained in known manner by reacting mono-nuclear or poly-nuclear polyphenols, advantageously diphenols, with epichlorhydrin or dichlorhydrin in the presence of an aqueous alkali, whereby, depending on the molecular ratio of the components used, mixtures of different polyethers having chains of difierent lengths and epoxide groups predominantly in end positions and, if desired, intermediately placed hydroxyl groups, for example, of the following constitution:

in which the atomic grouping 0R0 may represent, for example, the radical of a so-called diphenol, that is to say, for example, a compound of the type of 4:4'-dihydroxydiphenyl-dimethylrnethane, or resorcinol.

Aliphatic alcohols and epichlorhydrin can also be converted into chlorhydrin others With the aid of condensing agents such as boron trifluoride, which chlorhydrin ethers change into compounds containing epoxide groups by the elimination of hydrogen chloride by means of an efficients of thermal expansion of resin and metal.

agent of alkaline reaction. Furthermore, it is possible to obtain substances containing epoxide groups by treating compounds containing olefinic double bonds with oxidizing agents, for example perbenzoic acid, or with hypochlorite.

It is of advantage to use starting materials containing epoxide groups in which there is a certain distance between atleast two of the epoxide groups. The epoxide groups may be connected to one another in various ways. Generally speaking it can be said that when the active groups of the cross-linking agent are relatively far apart the distance between the epoxide groups may be smaller.

In order to produce artificial masses, which can be converted by heat and if desired with the aid of catalysts into hardened elastic artificial products, the compounds containing epoxide groups are mixed with the cross-linking agents and if desired, with catalysts. if the starting materials are liquid the mixture may be produced at room temperature, and if one or both of them are solid, the mixing is best conducted with the aid of heat in the form of a liquid melt. The use of high temperatures may also be of advantage when the starting materials are not easily compatible with one another. The mixture is then treated at a raised temperature unitl a clear melt is obtained.

Mixing may also be carried out in the presence of solvents, and in this manner, depending on the choice of the solvents, lacquers can be obtained ready for use, which yield elastic coatings.

However, it is also possible to obtain artificial masses which withstand storage and are liquid or at least thickly liquid at room temperature, and which can be used without any solvent at ordinary temperature, for example, for coating or casting, and which after application can be converted, for example, by heat treatment into the hardened and elastic state.

In this case the aforesaid products constitute solventfree lacquers and may also be used for adhesively uniting a very wide variety of materials, especially metals, as such or on other substrata.

The new products represent a considerable advance, for example, in the art of making cast products. Hitherto it has indeed been possible to produce large hardened bubble-free cast products with the aid of compounds containing epoxide groups. However, it has always been ditfcult to enclose large articles such as metal parts by casting resins, such as is frequently required, for example, in the case of electrical apparatus, because strains subsequently occur due to the difierence between the codifiiculties are overcome by means of the new elastic products even in the hardened condition, since an enclosure covering a large metal core and composed of the new artificial product exhibits no fissures even after a long time.

The relative proportions by weight of the cross-linking agent and the compound containing epoxide groups may vary within very wide limits. cross-linking of the compound containing epoxide groups is brought about with a proportion of the cross-linking agent such as contains in the active groups a number of active hydrogen atoms approximately corresponding to the number of epoxide groups present.

As catalysts there may be used basic and acid catalysts such as are in themselves known. Especially suitable are nitrogenous substances such as amides or amines, for example, triethylene tetramine and also, for example, sodium hydroxide or sulfuric acid. There may also be used substances of the type of Friedel-Crafts catalysts, for example, boron trifluoride. There are also cross-linking agents which act simultaneously as catalysts such, for example, as triethylene tetramine mentioned above and polyesters containing tertiary nitrogen atoms, for example, a polyester obtained from adipic acid and ethyldiethanolamine, or from sebacic acid and triethanolamine.

The hardenable artificial masses or their components These Advantageously the r like product.

may be mixed at any stage prior to hardening with filling materials, softening agents, coloring substances etc. The invention also includes the possibility that a part of the cross-linking agent, especially when it is used in large quantities, does not react completely and therefore acts as a softening agent.

The terms hardenable and harden" are used herein not in a mechanical sense but with reference to the chemical properties or reactions. Those terms denote the capacity for conversion and the actual conversion, respectively, from a soluble and fusible condition into an insoluble and infusible condition. Accordingly, chemical hardening may lead to products which are mechanically very soft.

The following examples illustrate the invention, the parts being by weight:

EXAMPLE 1 730 parts of adipic acid (5 mols) and 248 parts of glycol (4 mols) are heated up to 220 C. The water formed during the reaction is distilled, and the last traces thereof are removed with. the aid of reduced pressure. There is obtained a mass which is salve-like in the cold, and contains 2.5 free acid equivalents per kilogram as determined by titration. This corresponds to a mixture of compounds in the nature of long chain polyesters having two end carboxyl groups, that is to say corresponding to dicarboxylic acids having an average molecular weight of about 800 and an average of about 44 members in the chain.

In order to prepare a product containing epoxide groups 228 parts of dihydroxy-diphenyl-dimethyl methane (1 mol) are reacted with 148 parts of epichlorhydrin (1.6 mols) and an aqueous solution of caustic soda, and the product is washed and dried. A brittle resin is obtained which contains about 2.4 epoxide equivalents per kilogram and is hereinafter referred to as product A.

Equal parts of the two products obtained as described above are melted together, for example, at 100 C., to produce a mixture which is thinly fluid at 100 C. and withstands storage and is thickly liquid in the cold. The mixture is heated in an open vessel for 16 hours at 165 C. to produce a transparent soft rubber-like artificial product of high elasticity. The new product exhibits no thermoplastic character, and does not fuse even at very high temperatures. By heating .the mixture for 48 hours instead of 16 hours, practically the same product is obtained. 7

The hardening of the cast products can be increased by the addition of phthalic anhydride. Thus, by'using 1 part each of product A and the dicarboxylic acid and 0.12 part of phthalic anhydride, there is likewise obtained a pourable mass which withstands storage and which is hardened, for example, by heating for 16 hours at 165 C. or by heating for hour at 220 C., to form a rubber- Also with this mixture very large bubblefree cast bodies can be obtained, which may if desire have metal bodies embedded therein.

Even harder products are obtained by melting together, for example, 1 part of product A, 0.65 part of the crosslinking agent described above and 0.15 part of phthalic anhydride. Such a mixture hardens after 5 hours at 165 C. In the form of a plate having a thickness, for example, of 12 mm., the product is difiicult to bend without breaking, but in the form of thin layers about 1 mm. thick it 7 can be completely folded without breaking.

The hardness of the final product can be varied within wide limits, not only by the addition of phthalic anhydride, that is to say, by means of a cross-linking agent having a distance between the active groups of less than 10 members, but also with the aid of quantities of the cross-linking agents characteristic of the present invention. For example, by melting separate'portions of 1 part of product A with 0.26, 0.67, 0.83, 1 .00, 1.25 and.l.5 parts, respectively, of the long chain dicarboxylic acid, and hardening the mixture for 16 or 48 hours at 165 C.

5 in a suitable vessel there are obtained cast products which In all cases there are obtained cast products which at the extend over the whole range from hard to quite soft rubbeginning of the series are still soft but towards the end ber-like products. of the series are rather hard.

EXAMPLE 2 The phthalic anhydride may here react in two different 5 ways. Firstly, it may react with the two end hydroxyl groups of the polyester, whereby a long chain dicarboxylic acid is formed, which as a multi-membered cross-linking agent enters into reaction with the epoxy-compound. However, it is also possible that it enters into reaction di- 19 rectly with the epoxide groups or with any hydroxyl groups present in the epoxy compound.

Cross-linking when hydroxyl groups are used as active groups can also be accelerated by means of catalysts. For example, by mixing 1 part of the molten polyester with 0.006 part of a solution of 32 per cent strength of boron trifiuoride in anisole, melting the mixture with 1 uses sebacic acid as the cross-linking agent is not included part product and hardening at 9 mass in the Praswt invention, Since in this Case the number gelatimzes even after /2 hour and there is obtained after of members in the chain is only 8. The resulting prod- Y a w hours a Clear, elatic molding- If them is nets are correspondingly hard and not elastic: used instead of boron trlfiuonde, 0.01 part of concen- In the following table are given the results of hardening mixtures of product A with various polyester-like dicarboxylic acids obtained in a manner analogous to that described in the first paragraph of Example 1. The hardening periods do not represent minimum periods. In the last column the properties of the elastic moldings are given. The numbers of members in the chain represent average values which are calculated both on the basis of molecular ratios and ascertained by acidimetric titration, these two values having been found always to agree well.

It is necessary to explain that the experiment (f) which Table Hardenable mixture of 1 part of Number product A and- Crosslinking agent (V), starting mateof mern- Hardening Remarks rials Tllnershn Pa t f t e 0 am r 0 Parts of phthafic anhydride 0.33 16 hours at 165 0... rather hard. 0.66 -.do rather soft. (a) 3 mols of adipic acid; 2 mols of glycol 24 1.00 ..do. Do.

1. 33 do very soft. 0.66 0 1 .do rather soft.

0.2 do.. rather hard. 0.4 do... 0. (b) 2 mols of adipic acid; 1 mol of glycoL- 14 0.6 do rather soft.

0.8 do.. Do. 1.0 do very soft. 1. 3 40 hours at 8". still liquid. (c) 10 mols of adipic acid; 9 mols oi glycol" 100 "'"i' 3% gf 1. 0 (1 soft. (d) 4 mols of adipic acid: 3 mols of 2:3- 34 1. 0 Do.

butylene glycol 1. 0 Do. 1. 0 Do. (e) 4 mols oi adipic acid; 3 mols of ethyl- 46 1. 0 rather soft.

hexane-ch01 1. 0 D0.

1. 0 rather hard. 0.2 hard. (1') Scbacic acid 8 0.3 Do. 0.5 Do. 0.6 soit. (g) 3 mols of sebacie acid; 2 mols of di- 42 3g:

glyc 1. 33 very soft.

0.2 hard. 0. 4 rather hard. (h) 3 mols 0t succinic acid; 2 mols of di- 24 0.6 solt.

glycol 0. 8 Do. 1. 0 Do.

EXAMPLE 3 trated sulfuric acid gelatinization occurs at about 160 C. after 1 /2 hours. After 22 /2 hours there is likewise 438 parts of adipic acid (3 mols) and 248 parts of obtained a clea al a t d t b glycol (4 mols) are heated toggther as descnbed m Exening neriods tiie pr d hc t e gn s to b eidi r i chl fzd hard am le 1 u to 210 C. The resultin ol ester contains I 341 111015 if nd y y grows P i g It is 13y mixing 1 part of the above described polyester from therefore a dialcohol having abbut 32 members in the amp}? and glycol Wlth part of an ethyl alcohohc a solution or 10 per cent. strength of sodium hydroxide and chain. 0 a

By melting 1 part of product A (prepared as described evappratmg alcohol at hlgh mature there obtained a neutral mass which contains 1 per cent. ot

in Example 1) with 0.8 part of the aforesaid dialcohol at about 100 C. and treatin the mixture for 16 hours Sodlum hydroxlde m the 9 of the sodlum Salt of drolyzed ester groups of the polyester. By melting the at 165 C. practically no change occurs. The product 'ltm mass with 1.4 arts of roduct A and hardenal 0 st1l flu1d at room tem erature. However b heat- 1 g p p 15 s 1 P y mg at about or C., gelatinization occurs after t c o mg he mlxture 16 hours at 220 C a bubble free 1% or A of an hour, respectively. After a total hardenrubber-like cast product is obtained. 1 1

The reaction can be accelerated with the aid of phthalic {mg Period of 2/2 or 1/2 hours respecwdy the macho is complete, whereby very slightly turbid, very soft, rubanhydride as a cross-linking agent having in the chain b lik t d t d less than 10 members, products with varying degrees of 70 er- 6 Gas pro s are 0 Lame elasticity being obtained depending on the quantity of the EXAMPLE 4 Phthahc anhydnfie as Flamed below; Ammonia is passed through the molten polyester of 562311116 P0111011S of 1 P each the: above mlxmre Example 1, which contains 2.5 free acid equivalents per are With 0.17, and part Of kilogram, at about 200 for 2 hours and then the exphthalic anhydride, and heated for 16 hours at C. 7 cess of ammonia is driven off. There is obtained a prodrequires 7 hours.

7 parts of product A the mass begins to gelatinize at 160 C. even after 2 hours, and after 4 hours a rather harder elastic cast product is obtained. At 140 C. hardening EXAMPLE 5 548 parts of adipic acid (4 mols) and 400 parts of ethyl-diethanolamine (3 mols) are esterified as described in Example 1. There is obtained a liquid polyester hav ing an acid equivalent of 2.23 mols per kilogram, which agrees exactly with the calculated value. The polyester contains 3 basic tertiary nitrogen atoms in the chain and in all about 43 members. V

Portions of 1 part each of product A (obtained as described in Example 1) are mixed with 0.4, 0.6, 0.8, 1.0 and 1.2 parts of the above mentioned polyester and hardened for 16 hours at 165 C. The first product is rather hard while the subsequent products are progressively softer.

The basic nitrogen atoms in the molecule of the above polyester cause this cross-linking agent to act simultaneously as a catalyst. Thus, if product A is treated at 165 C. on the one hand with 0.6 part of the above ester,

and on the other with 0.6 part of the polyester described in Example 1, which contains practically the same member of members, in the first case gelatinization occurs after 1 hour while in the second case this requires 6-7 hours.

EXAMPLE 6 as described in Example 1, are melted together, cast and hardened for 16 hours at about 160 C. A very soft rubber-like cast product is obtained.

EXAMPLE 7 By using in the second paragraph of Example 1, instead of 1.6 mols of epichlorhydrin, only 1.4 mols thereof a resin melting at a higher temperature is obtained which contains only about 1.5 epoxide equivalents per kilogram and of which theepoxide groups are at a greater distance from one another than in product A of Example'l.

1 part each of the above product and of product A are melted with -1 part of a polyester obtained from 4 mols of adipic acid and 3 mols of ethylhexane-diol and hardened for 16 hours at 165 C. In both cases rubberlike cast products are obtained, the first mentioned mixture being considerably softer than the second melt.

EXAMPLE 8 In a manner analogous to that described in the second paragraph of Example 1 there is obtained from epichlorhydrin and dihydroxy-diphenyl-dimethyl-methane an epoxy-compound. By using a large excess of epichlorhydrin it is possible to obtain a still liquid product of relatively low molecular weight, which contains 4.8 epoxidc equivalents per kilogram.

Separate portions of 11 parts each of the above product are melted with 15, 17.5, and 21.5 parts of the polyester obtained as described in Example 1. There are obtained liquids which are stable and viscous in the cold and which harden in molds, for example, in 15 hours at 160 C., and give clear rubber-like cast products.

8 EXAMPLE 9 15 parts of a liquid consisting essentially of compounds containing about two epoxide groups and having an epoxide equivalent weight of about 170 (prepared from epichlorhydrin and glycol as described on page 5 of British Patent No. 518,057) are mixed with 15 parts of the polyester of Example 1 above and 1.7 parts of maleic anhydride and hardened at 160 C. After 40 minutes the mass is gelatinized. After a total hardening period of 1 hour a clear bubble-free soft rubber-like cast product is obtained.

EXAMPLE 10 1 part of diglycide ether is mixed with 6 parts of the polyester of Example 1 and treated for 16 hours at 165 C. The product is still liquid. On the other hand, by using 1 part of diglycide ether with 3 parts of the polyester and 0.5 part of phthalic anhydride there is obtained under the same reaction conditions a solid jelly-like mass.

A similar mass is obtained by hardening 1 part of the glycide ether of glycerine with 3 parts of the polyester of Example lunder the conditions given above.

The aforesaid glycide ether of glycerine is obtained by.

the condensation of glycerine with epichlorhydrin in the presence of boron trifluoride as catalyst, and subsequently EXAMPLE ,11.

A mixture of 1 part of product A and 0.6 part of the product described in the first paragraph of Example 1 is mixed with the quantities of vtriethylene tetramine as catalyst given below (the parts being calculated on the mixture) and hardened and the time required to harden the moldings ascertained:

(1) 0 part, 48 hours, C., still completely liquid.

(2) 0.004 part, 12 hours, 100 C., hardened, soft and rubber-like.

(3) 0.008 part, 9 hours, 100 C., hardened, soft and rubber-like.

EXAMPLE 12 Dehydrated castor oil is converted as described in industrial and Engineering Chemistry, vol. 38, page 1139 (1946), into the methyl ester of the corresponding acid, and the product is then polymerized under the conditions described in that publication and hydrolyzed. There is obtained a product having an acid number of 227.

According to the information given in Industrial and Engineering Chemistry, vol. 33, page 89 (1941), this product consists of hydrocarbons containing as substituents two or three carboxyl groups respectively, which groups are separated from one another by 18 or 16 members, respectively.

4 parts of the above acid are melted together with 5 parts of product A prepared as described in Example 1. The mixture is at first turbid at temperatures below C. 1

However, by treating the mixture for /2 hour at C., a melt is obtained which remains clear even after cooling and solidifies to a viscous fusible mass. 1

This product is applied in the Warm state to a metal plate and the coating is hardened for 6 hours at 165 C A coating which adheres well and is very elastic even when thick is obtained.

EXAMPLE 13 606 parts of sebacic acid 3 mols) and 149 parts of triethanolamine (1 mol) are esterified in a manner" analogous to that described in the first paragraph of Example 1. A product is obtained which contains 3.67 acidequivalents per kilogram (the pure tris-sebacic acid monoester of triethanolamine containing 4.28'free acid groups per kilogram). It therefore consists at least in U part of a compound containing three carboxyl groups which are separated from one another by 25 members.

Two portions of 1 part ea h of the above product are mixed with 1 part and 1.25 parts respectively of product A (prepared as described in Example 1) and there are obtained artificiat masses which when hardened for about 10 minutes at 165 C. or for about 2 hours at 100 C. yield rubber-like masses. The short hardening periods show that in this case the cross-linking agent also functions as a catalyst owing to its basic nitrogen.

What is claimed is:

1. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two groups which react with epoxide groups, which reactive groups are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, the reactive groups being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, imino and imido groups, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

2. A process as in claim 1 wherein said compound containing at least two groups which react with CPGXldC groups is a polyester.

3. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two reactive groups which react with epoxide groups, which reactive groups are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, the reactive groups being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, irrino and imido groups, and the reaction with heat being carried out in the presence of a catalyst to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

4. A process for the manufacture of an eiastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two groups which react with epoxide groups, which reactive groups are separated from one another by a chain or" at least 14 members, in which chain a rigid ring is counted as one member, the reactive groups being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, imino and imido groups, said cross-linking agent containing basic groups in addition to the said reactive groups, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

5. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two groups which react with epoxide roups, which reactive groups are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, the reactive groups being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, imino and imido groups, said cross-linking agent containing a tertiary nitrogen atom in addition to the said reactive groups, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

6. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two basic groups which react with epoxide groups, which reactive groups are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

7. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two carboxyl groups which are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

8. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two carboxyl groups which are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, and the reaction with heat being carried out in the presence of a catalyst to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

9. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mol with, as cross-linking agent, a compound containing at least two carboxyl groups which are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, and the reaction with heat being carried out in the presence of a basic catalyst to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

10. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mole with, as cross-linking agent, a polyester containing two carboxyl groups which are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, and the reaction with heat being carried out to a point where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

11. A process for the manufacture of an elastic artificial product which consists essentially of reacting, with heat, a compound containing more than one epoxide group per mole with, as cross-linking agent, a polyester containing two carboxyl groups which are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, the crosslinking agent containing in addition basic groups, and the reaction with heat being carried out to a point Where the reaction mass becomes infusible, whereby an elastic product is obtained, said elastic product containing said chain of at least 14 members intact.

12. A composition of matter capable of forming an elastic infusible reaction product, which consists essentially of a hardenable epoxide compound having more than one epoxide group per mol and, as a cross-linking agent, a compound containing at least two radicals which are capable of reacting with the epoxide groups, said radicals being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, imino and imido radicals and being separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one member, said elastic product containing said chain of at least 14 members intact.

13. A composition in accordance with claim 12, wherein the cross-linking agent is a polyester containing carboxylic radicals as the reactive radicals.

14. A composition in accordance With claim 12, wherein' the cross-linking agent is a polyester of adipic acid with glycol.

15'. An elastic infusible product which consists essentially of the reaction product of a compound containing more than one epoxide group per mol with, as crosslinking agent, a compound containing at least two groups which react with epoxide groups, which reactive groups are separated from one another by a chain of at least 14 members, in which chain a rigid ring is counted as one 20 member, the reactive groups being selected from the group consisting of carboxyl, sulfo, phosphoric acid, amino, amido, imino and imido groups, said elastic product containing said chain of at least 14 members intact.

References Cited in the file of this patent UNITED STATES PATENTS 2,324,483 Castan July 20, 1943 2,403,343 De Groote July 2, 1946 2,494,295 Greenlee Jan. 10, 1950 2,506,486 Bender et a1. May 2, 1950 2,510,885 Greenlee June 6, 1950 2,558,949 Greenlee July 3, 1951 2,591,539 Greenlee Apr. 1, 1952 2,676,162 Marotta Apr. 20, 1954 OTHER REFERENCES The Svedberg (Upsala), 1944, pages 234-45. Carothers: Collected Papers on Polymerization by Mark and Whitby (Inter-science), 1940, pages 63-65. 

1. A PROCESS FOR THE MANUFACTURE OF AN ELASTIC ARTIFICIAL PRODUCT WHICH CONSISTS ESSENTIALLY OF REACTING, WITH HEAT, A COMPOUND CONTAINING MORE THAN ONE EPOXIDE GROUP PER MOL WITH, AS CROSS-LINKING AGENT, A COMPOUND CONTAINING AT LEAST TWO GROUPS WHICH REACT WITH EPOXIDE GROUPS WHICH REACTIVE GROUPS ARE SEPARATED FROM ONE ANOTHER BY A CHAIN OF AT LEAST 14 MEMBERS, IN WHICH CHAIN A RIGID RING IS COUNTED AS ONE MEMBER, THE REACTIVE GROUPS BEING SELECTED FROM THE GROUP CONSISTING OF CARBOXY, SULFO, PHOSPHORIC ACID, AMINO, AMIDO, IMINO AND IMIDO GROUPS, AND THE REACTION WITH HEAT BEING CARRIED OUT TO A POINT WHERE THE REACTION MASS BECOMES INFUSIBLE, WHEREBY AN ELASTIC PRODUCT IS OBTAINED, SAID ELASTIC PRODUCT CONTAINING SAID CHAIN OF AT LEAST 14 MEMBERS INTACT. 